The Y2K crisis that never happened: Part 1

Thousands of computer programs failed on 2000-JAN-1, but the effect was minor:

Almost all of the software failures and disruptions materialized in aged accounting software used by countless small businesses. Very few major failures were reported:

	A programming bug was reported in Britain near the end of 1999-DEC. Bank computers started to reject credit card purchases. Their program not only checked that the credit card was valid; it checked whether the card would also be valid a few days in the future. When this day fell in the year 2000, a Y2K bug sprang to life and rejected cards in large numbers.
	The "Criticall" system in Toronto, ON, Canada, failed on New Year's day. This monitors hospitals and directs  patients in ambulances to emergency rooms that are not hopelessly overloaded. It was quickly repaired. In the meantime, a backup system was used.
	There were minor failures in monitoring systems at seven nuclear generating stations in the U.S. None represented a safety problem or caused interruptions of power.
	There were a few control problems at some airports which were fixed quickly.
	Data from a U.S. defense department satellite was unusable for a few hours in the morning of JAN-1; a backup system took over until the system could be reprogrammed.
	According to the Church of Jesus Christ of Latter-day Saints, the LDS Church, some minor problems were reported in parts of Russia's telephone system.
	A computer system in South Korea issued court summonses to 170 people to appear for trial on 1900-JAN-4...or else!
	A TV weather map in France showed the year as 19100.
	A control system at a power plant in the U.S. Midwest jumped ahead 35 days. However, the electrical supply was not affected.

Failures occurred for one of two reasons:

In the early days of business computing, many programmers did not see too far into the future, and took shortcuts: In those days, disk and memory space were costly, and so many programmers used only 2 digits to record the year. For example, they used 72 represented 1972. The problem is for 2000-JAN-01 and later dates, many of these programs would have decoded the new year as 1900.  Other programmers used the year 00 or 99 to indicate an error condition. They did not expect their programs to last until 1999 or 2000  Other programs stored the year unambiguously, but then interpreted the year as if it occurred in the 20th century. So, 1972 was stored properly, but only the 72 was interpreted by the program, which added a 19 prefix. In the year 2000, such programs might have continued to add the prefix, resulting in the year 1900. Still other programs will produce unpredictable results. 2,3 All of these deficiencies would have caused major chaos. However most programs were either fixed or replaced before a Y2K bug surfaced.

As a convenience for persons entering dates form a keyboard, programs were frequently written to accept only two digits for the year. The program then added "19" as a prefix to the entered date to generate a full 4 digit year. When these programs are run during the year 2000, the operators will enter "00" for the year and the program will add the "19" prefix to produce the year "1900". One example is Windows 98. The Date tab in "Regional Settings Properties (accessible from Start, Settings, Control Panel) gave two dates, typically 1930 and 2029. When a 2 digit number (e.g. 99) is entered, the system interpreted the date as being between these years -- i.e. 1999. Unless these settings are changed, a "30" year which may be intended to represent 2030 will be interpreted as 1930. This bug paled in comparison with all the other bugs in Windows 98.

The American National Standards manual states: "2.3: Year shall be represented as four digits with the option of omitting the two high order digits (commonly referred to as century) as required in applications where century is to be implied." Unfortunately, too many computer programmers felt that it was safe to imply "19" as the century. They expected their programs to be long gone by 2000. Many of these legacy programs lasted into the 21st century; a few are probably still functioning on computers around the world.

Many companies neatly sidestepped the problem by upgrading their accounting and process control software to entirely new standard programs that are free of the Y2K bug. "Cynics claim the millennium bug scare is being spread by certain computer supply firms which will earn huge sums by selling pricey equipment they maintain is necessary to alleviate the problem." ₄

Others have mounted massive projects to have programmers scan their software - some of it decades old - and correct any problems.

Date notations will cause confusion:

Traditionally, people have used two digits to represent years. Three all-numerical methods are now in common use. February 15, 1999 in various countries, is shown as:

	mm/dd/yy (2/15/99)  This is a common notation in the U.S.
	dd/mm/yy (15/2/99)  This is a common notation in Canada.
	yy/mm/dd (99/2/15)  This is common internationally.

We play it safe on this website by defining dates like 2000-FEB-15. No ambiguity is possible. However, it is not very efficient either.

For years, there has been a confusion between the first two notations. People are unsure whether the first number refers to the month or the day. In the year 2000, there should be no more confusion than normal, because the year will be clearly identified as "00". Unfortunately, starting in 2001, years will be shown as 01 for 2001, 02 for 2002, etc. Much confusion will be created. For example, consider 01 02 03. Does it mean January 02, 2003 or 01 February, 2003 or 2001 February 03? This problem will continue, in diminished form, until the year 2032. This is one of the reasons why this web site always uses the unusual convention of a 4 digit year, three letter month and two number day. (e.g. 1999-JAN-15) . This format, and the similar all numeric version (e.g. 1999-02-15), are clear and unambiguous. They are commonly used outside of North America. The latter, all numeric, format is ideal for computers, because it can be followed with the time of day, and facilitate chronological sorting, as in: 2001-01-15 12:34:56.78

Personal Y2K problems: 

Although the average house probably has dozens of microcomputers imbedded in various appliances, few keep track of the year, and thus did not fail at the start of the year 2000.  One exception might have been those computers in some cars that keep track of the date of the next maintenance check. However, the media did not report any failures. Some older digital watches and video cameras may have needed their dates reset. Personal computers are a different matter. New versions of programs that are Y2K compliant, and programs that check PC compliance were made available. ₅  

A minor nuisance was experienced by many users of old versions of Web browsers. They received a scary notice after 1999-DEC-31 that told them that the certificate authority that identifies the site for encryption purposes has expired. The browser worked as before. However, the same notice reappeared until the browser was updated. Although updates are free, they took hours to download over the Internet via a slow modem. 

Many small businesses suffered a failure in their accounting and billing software. No programs at North American banks are known to have failed. ATMs/ABMs continued to work without a hitch.

Many North Americans kept hard copies of their bank and business transactions, investments, payments, bills etc. just in case. The U.S. federal government set up a consumer hotline at 1-888-USA-4-Y2K and a web site at http://www.y2k.gov. Micro Support Bureau had an online list of "software to check/fix/report on Y2K issues" on your PC. ₆ Microsoft had a web site to help people update their Microsoft products to be year 2000 compatible. ₇